xibosignage#227

…t matter but incase there is a delay opening the media we do it)

Added a manager to download content from Adspace, unwrap if necessary and add to an ad buffet.

Add schedule, layout parsing, and impression recording.

Ensure download happens after request + second chance to add to cache, 0 duration in schedule manager causes issues,

Add sensible timeouts and store/forward for impressions.

Initial work tracking widget groups.
Parse widget groups when creating a layout.

Initial work tracking Layouts inside a Campaign when cycle is enabled.
Initial work selecting the right layout when getting next layout.

Missed parsing the schedule in ParseCyclePlayback

Working prototype for testing.

… which doesn't match the player window.

Fix zindex issue.
xibosignage#237, xibosignage#238